Book Image

OPNsense Beginner to Professional

By : Julio Cesar Bueno de Camargo
5 (1)
Book Image

OPNsense Beginner to Professional

5 (1)
By: Julio Cesar Bueno de Camargo

Overview of this book

OPNsense is one of the most powerful open source firewalls and routing platforms available. With OPNsense, you can now protect networks using features that were only previously available to closed source commercial firewalls. This book is a practical guide to building a comprehensive network defense strategy using OPNsense. You’ll start with the basics, understanding how to install, configure, and protect network resources using native features and additional OPNsense plugins. Next, you’ll explore real-world examples to gain in-depth knowledge of firewalls and network defense. You’ll then focus on boosting your network defense, preventing cyber threats, and improving your knowledge of firewalling using this open source security platform. By the end of this OPNsense book, you’ll be able to install, configure, and manage the OPNsense firewall by making the most of its features.
Table of Contents (25 chapters)
1
Section 1: Initial Configuration
6
Section 2: Securing the Network
13
Section 3: Going beyond the Firewall

Network diagnostics and troubleshooting

It's important to know how to configure network interfaces in OPNsense, but it is more important to know how to solve problems related to it. In this section, we'll explore the common issues and see how to solve each one.

First of all, let's see what diagnostic tools are available in WebGUI.

All of the following options can be accessed from Interfaces | [tool name]:

  • ARP Table: This page lists the operating system ARP table, in which you can find the IP and MAC addresses listed in the following fields:
    • Device Manufacturer, based on MAC OUI (organizationally unique identifier)
    • Interface, using the FreeBSD NIC name
    • Interface Name, using the configured one in the OPNsense interface description
    • Hostname, if it resolves hostnames
  • NDP Table: Like the ARP Table page, this page will show the same information fields, but for IPv6 addresses based on the Neighbor Discovery Protocol (NDP). Due to the similarity with ARP, you can...